Field of the Invention
This invention relates to an industrial truck with a load handling device for the handling of a load carrier. The load handling device is formed by a load fork that includes two fork tines. The load handling device has a load carrier interlocking device for interlocking the load carrier being handled with the load fork.
Description of Related Art
Industrial trucks, such as order picker trucks in the form of vertical pickers, have a driver's cab with an operator's lift cage that can be raised and lowered. Located on the driver's cab is a load handling device which is formed by a load fork oriented in the longitudinal direction of the truck. The load fork is formed by fork tines. Order picker trucks, such as vertical pickers, are used in picking operations, rack systems, and for picking goods from higher-level shelves.
The load fork can be used to pick up a load carrier, such as a pallet, on which merchandise is loaded or unloaded during picking operations.
The purpose of the load carrier interlocking device is to secure the load carrier that has been picked up with the load fork to prevent it from shifting, tipping, or falling. It is particularly necessary to hold the load carrier on the load fork when, during picking operations, the operator of the industrial truck climbs onto the load carrier located on the load fork when the load fork is raised, and thus the load carrier located on the load fork is accessible to the operator.
EP 1 627 847 B1 describes a generic industrial truck equipped with a load carrier interlocking device. The load carrier interlocking device consists of two clamping levers that are biased toward a clamped position by a tension spring. By means of a drive system formed by a spindle drive with an extendable spindle or a piston-cylinder system, the two clamping levers can be actuated into a release position. To pick up a load carrier, the clamp levers are actuated by the drive device into the release position, so that the clamp levers are opened wide enough and a foot part of the load carrier can be inserted between the opened clamping levers. To secure the load carrier that is being picked up if the load carrier is picked up completely, the clamp levers are actuated by the drive system into the clamping position, in which the clamping levers are in contact against the foot part of the load carrier and the tension spring exerts a corresponding clamping force on the foot part of the load carrier. On account of the need for a drive system, a load carrier interlocking device of this type is complex and expensive to build. It is also more complicated to operate because, before picking up a load carrier, first the clamping levers must be actively actuated by the drive system into the open position and, after the load carrier has been picked up, the clamping levers must then be actively actuated by the drive system into the clamping position. This system also poses a risk of incorrect operation or operator error. If the clamping levers are not actuated into the clamped position when the load carrier is picked up all the way, the picked up load carrier is not secured, and the load carrier that has been picked up is not secured in the event of a failure of the energy supply from the drive system of the load carrier interlocking device.
An object of this invention is to provide an industrial truck of the general type described above, but in which the load carrier interlocking device is simple and economical to construct, offers safe, simple, and reliable operation, and with which a load carrier that has been picked up can be held securely.